Rock-drill



(No Model.)

J. P. SIMMONS.

ROCK DRILL.

Patented Mar. 29, 1898.

be effective in operation.

by means of the devices illustrated in the ac U ITED STATES PATENT OFFIcE.

JOHN P. SIMMONS, OF SAN FRANCISCO, CALIFORNIA.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 601,288, dated March 29, 1898.

Application filed March 10, 1897. Renewed February 28, 1898. Serial No. 672,095. (No model.)

Drill, of which the following is a specification."

My invention relatesto the class of percussion-drills in which the drill is'actuated by compressed air or steam in a direct-action englne.

It consists in the novel construction, arrangement, and combination of the several parts which I shall hereinafter fully describe and. specifically claim.

The object of the invention is to provide a rock-drill of simple construction which shall This I accomplish companyin g drawings, in which- Figure 1 shows alongitudinal section. Fig. 2 shows a cross-section through the valvechest.

Referring to the drawings, A is a cylinder provided with a valve-chest a of cylindrical tral bolt a suitably packed to make it airtight. Two inlet and. two exhaust ports, re.- spectively, a a and a a, areprovided, one to each end of the cylinder. A suitable inlet a for compressed air, opening into the valvechest, is also provided.

B is a short rock-arm loosely journaled upon bolt a It is provided with two cylinders or sockets b 12, into each of which is fitted a boss or plug 0, projecting from the back of a slide-valve O. The bottom of each socket is raised in conical formand is provided with a spring-ring D of smaller diameter than the base of the cone. Upon this ring rests the plug of the valve. A tappet b is formed upon the lower side of both extremities of therockarm 13, projecting into the bore of the cylinder. E is a piston having a portion of its length intermediate of its ends smaller in diameter than the bore of the cylinder and its smaller and larger diameters connected by a tapering portion, as shown in Fig. 1. end of the piston is provided with a suitable piston-rod, which passes through a detachable closely-fitting sleeve F. This sleeve at the cylinder end is bored out for a portion of its length of a larger diameter than the rod. It is also bored for a short distance from the same end'of a still larger diameter, preferably slightly larger than the cylinder-bore. Into the annular space thus formed around the piston is fitted a gland or shouldered sleeve G, the sleeve portion of which is some what shorter than the annular space into which it fits, thereby leaving an annular space around the piston-rod, into which is placed any suitable packing, here shown as metallic rings. The sleeve Gis secured to the cylinder by bolt and nut or any other suitable means.

I is a feed-nut, its length cut into two sections 41 and t". The section 2" is provided with a recess i and the inner surface of the pocket in which the nut fits is provided with a fixed projection corresponding with and fitting'into the recess 4?. The outer end of section '0' is provided with a lug 2' projecting radially from the nut. A portion of the side of the nut-pocket is removed to receive the lug i the width of this removed portion being wider than the lug, as shown at 2", Fig. 2. A clamp J secures the nut in place.

v The rock-arm B is rocked upon its pivotal bolt a and consequently the valves 0 0 close and open the inlet and. exhaust ports alter nately of each end of the cylinder by engagement of the inclined portion of the piston E with the tappets I) Z) of the rock-armat each stroke.

Owing to the construction described only a small portion of the back of each valve 0 C is exposed to pressure, thus reducing thefriction-and wear on valve and seat.

The fastening of the sleeve F in place also secures the sleeve G and packing around the rod. The flange on G serves also to center the sleeve F with the cylinder.

The radial recess 2", being wider than the lug '5 permits of some axial movement, thereby taking up slack of the threads.

Section '5 is held securely by pressure of clamp J. 7

What I claim as new, and desire to secure by Letters Patent, is-

The forward 7 seat, an incline and a spring-ring thereon adapted to operate by radial compression whereby the valve is kept in contact with its seat.

4. A device comprising a direct-acting engine and a feeding device comprising a feedscrew and a nut thereon made in two abutting sections, and means for partially rotating one of said sections whereby loose fit is taken up.

JOHN P. SIMMONS.

XVitnesses:

LINCOLN SONNTAG, II. G. OoRWIN. 

